Please help!! I'm at wits end. Diagnose "open circuit"?

[BulldawgSolar]

If you're getting 70-80% of rated in decent solar conditions, that's pretty much a win.

Glad to hear it's sorted!

When you have to mix panels on the same MPPT:

Parallel Vmp-Voc range should be very similar - within 10%
Series Imp-Isc values should be as close as possible. All panels in series will operate at the LOWEST rated current.

I've got the 100ws on one controller and the 210ws on a separate controller

 

[sunshine_eggo]

Actually, I should have asked if Over-Panelling by adding a 3 string of 100W to make 5S3P is advisable. Adding the 210W panels would be too close to max amperage for that controller

If a PV input current limit isn't published, its' generally accepted to be the same as the battery charge current.

 

[sunshine_eggo]

I've got the 100ws on one controller and the 210ws on a separate controller

Yep. I was just giving you the rules for use in the future if needed.

 

[BulldawgSolar]

Victron is very clear in their overpaneling criteria:

1) Never exceed Voc input limit.
2) Never exceed PV input current limit.

#1 needs a little head room for cold weather voltage increases, but you can run the amps right up to the limit.

This process is generally true for most MPPT even if it's not published. If MPPT place hard limits on the input, respect them.

The Sigineer currently supports the 5S2P 100w. It can support up to 4500w, 80a, 145v VDC.

My existing 5S2P is at 94.5v/10.6a for going to 5S3P would be 94.6v/15.9a. Well within limits.

Adding to the 210w with the Victron would be 37.5a, over the 35a limit

 

[sunshine_eggo]

The Sigineer currently supports the 5S2P 100w. It can support up to 4500w, 80a, 145v VDC.

My existing 5S2P is at 94.5v/10.6a for going to 5S3P would be 94.6v/15.9a. Well within limits.

Adding to the 210w with the Victron would be 37.5a, over the 35a limit

At 80A, you're not over-paneling with 5S3P. 4500W is max output. If you're under this, you're not over-paneled.

Over paneling would be 5S12P as that's more power than the MPPT can handle, but it's still under the max input limits.

EDIT: however much solar you hang on the MPPT, you need to make sure that you don't exceed your battery's charge current rating.

 

[littleharbor2]

210 watt panels have a voc. of 16.77? What is the vmp.? What brand and model panels are they?